The Twin Cities didn't receive any measurable snow Monday but upwards of 6 inches could pile up in the metro area as the snowstorm advances through the region for a second day on Tuesday.
The official prediction from the National Weather Service is 3-6 inches for the entire Twin Cities metro area: "Snow will become more widespread this morning, with travel impacts expected across the region. Here's how much more snow we're expecting by the time it ends Tuesday evening."
According to the NWS forecast discussion, isolated totals higher than 6 inches are possible, especially if heavy bands of snow develop.
What will be key is what type of ratios we are dealing with. What's that mean?
Meteorologist Sven Sundgaard says the optimal temperature for the highest snow ratios is between 0 and 10 degrees in the area of the atmosphere where the snowflakes literally grow.
Temps in that growth layer are too warm for a ratio of 20 inches of snow for every 1 inch of liquid, and while the temp in the growth layer will be dropping throughout the day, the best dynamics and moisture availability could be out of here by the time the temps reach that optimal range.
To put it simply: The higher the ratio, the faster the snow accumulates. And when the Twin Cities is dealing with 0.2 to 0.4 inches of liquid, the totals just aren't likely to pile up beyond that 3- to 6-inch range.
Sundgaard is giving the metro a 15-20% chance of getting 6 inches, so while it's not impossible, it's not the most likely outcome.
That's why the HRRR model, like you see below predicting 8 inches of snow in the metro, could very well be overestimating today's potential because the snow will be more dense, leading to a less efficient accumulation process.
Snow totals in Minnesota on Monday
17 inches - Duluth
17 inches - Nashua
13 inches - Wendell
12 inches - French River
9.5 inches - Evansville
9 inches - Lester Park
8.7 inches - 3 miles NE Duluth
8.5 inches - Mora
8.5 inches - Little Falls
8.5 inches - Federal Dam
8 inches - Battle Lake
7 inches - McGrath (6 miles SE of town)
7 inches - Glenwood
6.8 inches - NWS Duluth
6 inches - Hinckley
6 inches - Alexandria
6 inches - Grand Rapids
6 inches - Verndale
5 inches - Cloquet
5 inches - Pine Center
4.7 inches - Wrenshall
4.6 inches - Long Prairie
4 inches - Bemidji
2.6 inches - Onamia
1.3 inches - St. Cloud
You can find the latest snow totals from the NWS here.